I have a bag of lamps with no part number or identification. They appear
to be either 18V or 24V lamps, and a picture (85K or so) is at
http://www.rain.org/~marvin/lamps.jpg. Anyone know what these things are
used for?
Hi
Why not go with something like one of the DSP chips.
The ADSP218x family of parts are enough like a real processor
that one could do quite a bit. They don't require much
external glue parts and can bootstrap them selves from a flash
memory. The 2181 has 80K or so of internal RAM and
runs at around 30 mips ( or more for newer versions ).
You don't even have to deal with the DSP functions if
you don't want to. They are still a very powerful processor.
Things like bit-banging old flopy disk or tape drives
are well within it's capabilities ( I mean raw data ).
One can buy demo boards for around $100 and then make
add-ons to increase it's functions.
Anyway, just a thought.
Dwight
>From: "J.C. Wren" <jcwren(a)jcwren.com>
>
> If I were going for audience appeal, and you don't plan to be
>booting CP/M or some other free readily available O/S from the get-go,
>I'd aim for something that was was well supported. For me, SIMH was a
>powerful tool in getting the Z80 SBC up. I'd compile the BIOS under the
>SIMH Z80 emulator running CP/M, upload it to the Linux box, and download
>it to the ROM emulator. Turn around time was very quick.
>
> Problem is, Z80's aren't real interesting. There's lots of
>software, but they're kinda old hat. Homebrew 6502 systems seem a lot
>less common, making thier interest level, for me, higher. 1802's even
>more so. I would favor a CPU that has a static core. Being able to toy
>with the clock is helpful, especially in the early stages of bringup.
>
> While concievable that you could write a disk-based OS on a 8031,
>the architecture doesn't lend itself well to that. I'd pick something
>that has a real stack, with a real von-Nuemann architecture. Yes, you
>can play games with an 8031 and overlap the code and data space by
>AND'ing /PSEN and /RD, but the instruction set still lacks a real stack,
>and you're limited to 1.5 16 bit registers (I'm counting the MOVX @P2 mode).
>
> Obviously, building something with an external 32 bit bus is going
>to be more work than a 8 bit or 16 bit bus. 16-bit address and 8 or 16
>bit data would be middle of the road. Are you going to stick to 5V
>logic, or 3.3V? With 3.3V logic, you've got a lot more available
>choices, these days. If you wanted to play with an ARM core, as far as
>I know, there are no 5V ARM cores. Or if there are, they're not very
>common.
>
> One neat part is the Philips LPC2106. 128K bytes FLASH, 64K bytes
>RAM, all on chip. ARM core, timers, 2 serial ports, GNU tools readily
>available. But it's SMT only. And 3.3V I/O with a 1.8V CPU core.
>
> Something like a 6809 would be fun (I like those). When you're
>done, you could boot OS/9 or Flex/09. If you want to write on the bare
>metal, it's got a nicer instruction set than the Z80, but lacks
>registers. You make up for that with more addressing modes, and better
>relative branches. With a 6809E, the bus interface doesn't get much
>easier. The original 6809 was a lot more trouble to work with because
>of the clock requirements.
>
> 1802s are fun, too. The have a really neat instruction set that's
>way ahead of it's time, in some respects. It lacks a real stack,
>however, so you have to use 7 instructions are so to build a real stack
>in external memory. There's a fair amount of software, but CPUs are
>going for ~$10/ea, and the commonly availabel CDP1802ACE is only a
>3.2Mhz part. If you want the 5Mhz part, you need a CDP1802BCE, and
>those are going for a lot more money. The max specs say you can run a
>1802 at 6.4Mhz with 10V, but the > 5V parts are less common. You also
>have to use all CMOS glue logic. Single stepping and using switches to
>enter/edit memory is trivial. The CPU design supports that pretty much
>instrinsically, with little extra logic needed.
>
> Then there's the venerable 6800. Lots of software, lots of
>emulators, and OSs are available. Common, easy to find. Sorta like the
>Z80, though. It's common.
>
> You could build a 68000 system. Those are pretty easy to find, have
>good support, etc. 68K homebrew systems seems to be far less common
>than Z80s and 6800s. I don't know what support chips you'd need/want to
>make it play. I've used 68K systems, but never built my own. Slightly
>on the sluggish side, if you're looking for speed. I don't think the
>68Ks started getting fast until the 68030 or so. The 68020 was better,
>but still no speed demon, IIRC.
>
> The NSC32000 would be an uncommon homebrew system. Software may be
>hard to find, including emulators. I don't see a lot of 32K parts going
>by on eBay, so you might be hard pressed to come up with what you need
>one. Same for the Zilog Z8000.
>
> These are all the common 8, 16 and 32 bit systems I can recall. At
>some point, trying to homebrew something like an 80286 gets to be too
>much trouble. And little reward, in my book. I feel good everytime I
>throw away anything x86 that's less than an Athlon 1Ghz. And even those
>are getting ready to get moved to the "why bother?" list. There were
>some oddities, like the 6502 Forth chip, and several other Forth
>processors. I don't think I'd want anything with BASIC build in, like
>the 8031AH-BASIC (you said you wanted bare metal, anyway).
>
> Any basic families I missed here, not counting variants like 6510s,
>CDP1805s, etc?
>
> --jc
>
>Ron Hudson wrote:
>
>>
>> On Thursday, February 19, 2004, at 04:06 PM, Philip Pemberton wrote:
>>
>>>
>>> I'd be very tempted to add GPIB (aka HPIB, aka IEEE488) just because
>>> it's a
>>> very usable bus for connecting stuff like disc drives up.
>>>
>>>> Best use would be to connect it to a PC running a terminal emulator for
>>>> IO and Mass storage.
>>>
>>> I'd also add an IDE interface and an 80MB hard drive - fun factor
>>> again :)
>>>
>>
>> I suppose we'll have to take the busses out to an edge-card connector...
>>
>
>
The equipment has been spoken for. Thanks.> If anyone is interested in the
following, it is free for pickup (in the
> neighborhood of Salem, NH I believe).
>
> Please contact Marty at: mpdts20004 at yahoo.com
>
>=====
>
>> Hickok mdl 539B tube tester W/crt adapter
>> Dumont mdl 304-A o'scope
>> HP mdl 623B frequency/time counter
>> EICO mdl 304 signal generator (I built from a kit while attending Mass
>Radio School in 1961)
>>
>> Note: I haven't used any of this equipment since the 70's.
Ok, thanks to the cable Chris Bartlett sent me (thanks, Chris!) I was
finally able to bring up my Bernoulli box.
It seems the first drive system I tried has a problem. The driver does
not see the drive when it loads. The other unit is identified and comes
up just fine.
Now the problem is reading or formatting disks. I can't get a directory
listing or anything. I keep getting sector errors. Using the RCD utility
to perform a surface scan, I find that each disk I'm trying basically
fails at the same point. Sector #0 is always bad, then the rest of the
disk up to cylinder 195 or so verifies fine, and then the errors start
again. This is across the 10 or so disks I've tried.
I've tried cleaning the heads as best I can. I have a disk cleaning cart
but the pads were gone, so I replaced them with new pads (the fuzzy side
of some velcro patches) and ran that through the drive. It would be
otherwise very difficult to get at the head by disassembling the drive (I
tried) and besides, if the heads were still dirty they would not be able
to read any part of the disk, right?
Any pointers here? It seems odd that, with each disk, the first sector
would be bad but then the rest of the disk would be good, only to fail
again at a certain point. Was there ever a 20MB Bernoulli drive? If so,
my theory is that maybe these were written on a 20MB drive and I'm trying
to read them with a 10MB drive, and there's a format incompatibility.
Somewhat frustrating...
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
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>From: "Jules Richardson" <julesrichardsonuk(a)yahoo.co.uk>
>
>On Thu, 2004-02-19 at 23:43, John Lawson wrote:
>> On Thu, 19 Feb 2004, Jules Richardson wrote:
>>
>> > Polling list wisdom here...
>> >
>> > Hmm, any suggestions for anything creative to do with around 450 or so
>> > 5V relays? I have a bucket full here (literally).
>>
>>
>> Form? Contacts? terminal type?
>
>D'oh, I put that in and then managed to obviously slice it out before I
>hit send :/
>
>Majority of them are just DPDT types, with a few even just SPDT. Not, I
Hi
With as little as a SPDT, you can build all of the needed computer
functions. the DPDT gives one more freedom in design. Using
DC and blocking diodes adds another advantage. If I were going
to build such a machine, I'd build it as a single bit alu and
serial registers. I'd have a diode matrix with pegs or thumb
screws for program memory. I'm not sure how I'd deal with RAM.
Of course, using just relays would work but it'd be nice to
have some type of non-powered method. The early Zuse machines
had a mechanical setup ( that didn't work ). Maybe biased reed
relays is an option.
Bit width could be anything, even adjustable. Four bits is actually
quite useful and less waste compare with 8 bits when you consider
that a true false flag would waste an entire word width.
Dwight
>suspect, enough poles to do anything serious with. They're all
>PCB-mounting miniture types (honking great things with open contacts
>would be nice, but I wouldn't have the space to store them even if
>someone gave me a pile of them!). No idea of switch speed, but then
>maximum speed would not be a design goal anyway!
>
>They were pulled from a pile of phone exchange boards; the various CPUs,
>ROM, RAM and a few useful logic chips + transistors were what I was
>really after as usable spares, but it seemed a shame not to save all
>those relays too.
>
>cheers
>
>Jules
>
Any recommendations out there for good Nascom resources?
I know nothing about these creatures; I went round to pick up a Torch
floppy drive unit from someone a few days ago and they happened to ask
if I wanted a Nascom before they threw it out...
It's housed in the biggest, ugliest wooden case ever so that's going to
have to go! The system board is a Nascom 2, whilst the PSU says Nascom
3a - maybe there was a crossover point when that practice was common?
Inside there's just a system board and memory board, and no bus slots
for anything more - is the bus anything standard and were other 3rd
party boards typically added to these machines?
It's complete apart from a broken reset key on the keyboard (luckily
said key is seperate from the rest of the keys, so fitting any similar
sized switch would not look out of place). The clock circuitry looks to
be bodged to hell and back; there's even a bit of breadboard glued to
the inside of the case with an IC plugged into it :-)
Several stray wires are evident amongst the nest of ones which are still
attached to things, so it'll be a while before I can see if I can get it
running!
Still, a curious one, and my first wooden cased computer. I'll have to
keep an eye out for a better shell for it though... (actually I know
where there's some antique furniture rotting in an abandoned manor
house... I'll have to go looking for a suitable cabinet, maybe there's
something there I can use :-)
cheers
Jules
>From: "Don Maslin" <donm(a)cts.com>
>
>
>On Thu, 19 Feb 2004, Tony Duell wrote:
>
>> >
>> > Hard drives are almost always driven by a DC motor (off the +12v line).
>>
>> Perhaps you could tell that to my RK05s, RK07s, RL01s, RL02s, SA4000s,
>> etc, etc, etc.
>
>And the Quantum 8" fixed drives which used an AC motor and
>required different motor pulleys for 50 and 60 cps power.
>
> - don
>
Hi
I remember when I worked for Intel ( late 70's ). We bought
a number of things like printers and disk drives that were
for 220VAC/50Hz. On the disk drives, we used a file and some
fine sandpaper to reduce the pully size on the motor to work
with 60Hz. The voltage problem was solve by a transformer
the was to be used on the uScope product. They made nice
auto-transformers. The printer I modified just needed the
transformer and the change of a cogged belt pully. I bought
the pully from a place called Motion Industries. Now if it
was 24VAC/400Hz, that is a different conversion problem.
For those doing the auto-tranformer method, you need to
know that only half the power goes through the transformer
for a 110/220 or 220/110 change.
Dwight
A friend and I were discussing 8" floppy drives recently, in particular
that they often have two pulley sizes so that the rotational speed is
360rpm regardless of 50Hz or 60Hz operation, assuming that they are
setup properly.
The question then turned to whether or not a fixed hard drive would
typically be designed in a similar fashion, such that the spindle
would rotate at the same number of RPM when configured for 50Hz or
60Hz operation, or if they did not worry about the speed differences
as the media was not removable?
Of course todays modern hard drives are driven with DC motors, so
they are not affected by the A/C frequency differences.
Does anyone know what manufacturers routinely did on this account?
--tnx
--tom
>From: "Tom Uban" <uban(a)ubanproductions.com>
>At 10:14 PM 2/19/2004 +0000, you wrote:
>
>>On Thu, 2004-02-19 at 21:54, Vintage Computer Festival wrote:
>> > On Thu, 19 Feb 2004, John Honniball wrote:
>> >
>> > > Not many. You may find that only the high-volume distributors have
>> > > any of the 6502, Z80 or 6809 generation -- and you'd have to buy
>> > > in *huge* numbers. But having said that, many CPUs are simply not
>> > > made any more. So, you'd have to go to a specialist in obsolete
>> > > semiconductors.
>> >
>> > Or just sacrifice an old Apple //e (common as dirt) or C64 (common as
>> > lint) and use the chips inside.
>>
>>Well old process control equipment, especially telecoms hardware, tends
>>to be a good source of Z80 family chips, and typically there's no merit
>>in preserving the boards as they are.
>>
>>Better than wrecking a self-contained complete computer, even if it is a
>>common one!
>>
>>cheers
>>
>>Jules
>
>Z80s (and others) along with their support ICs are readily available from
>places like: http://www.jameco.com
>
>--tom
>
>
Hi
Still, all this stuff is from NOS ( New-Old-Stock ) as well as
bits and pieces from various manufacture stock rooms.
The most common 8 bit still in regular manufacture today
would most likely be the 8051 stuff from Philips. It is a
ugly processor to use as a general purpose processor but
quite nice for things like microwave oven controls. Large
memory access ( 64K ) is a pain.
Dwight
Some of you guys probably have piles of databooks lying around :-)
Can anyone tell me anything about a Philips MAB8031AH-12P CPU? Is it a
clone of anything more common? (given the 12MHz clock speed, 40 pin DIP
and a mid-80's build date, I doubt it)
There's a couple in each of the LVROM players that I'm trying to get
working, but I can't find any (accessible) data on the web about them...
(the ICs, not the players - I *may* have tracked down service manuals
for the latter)
cheers
Jules
